Fluid mechanical device for improved secondary mode IV delivery

ABSTRACT

A flow control system including: a tubing clamp that includes a clamping mechanism for holding closed a first fluid line while a second fluid flows along a second fluid line from a second container; a drip chamber having a one-way check valve; a vacuum activated catch retainably coupled with the tubing clamp and coupled with the second fluid line and including a movable element coupled with the tubing clamp, the movable element changing from a first shape to a second shape upon receipt of a deforming pressure, wherein when the movable element is in the first shape, the vacuum activated catch retains the tubing clamp in a closed position, and when the movable element is in the second shape, the vacuum activated catch releases the tubing clamp into an open position; and an infusion pump that draws a vacuum in the second fluid line.

CROSS-REFERENCE TO RELATED U.S. PATENT APPLICATIONS

This Application is related to U.S. patent application Ser. No.13/494,816 by Robert Dwaine Butterfield, filed on Jun. 12, 2012,entitled “DRIP CHAMBER,” and assigned to the assignee of the presentapplication. To the extent not repeated herein, the contents of thisrelated patent application are hereby incorporated herein by reference.

This Application is related to U.S. patent application Ser. No.13/494/874 by Robert Dwaine Butterfield, filed on Jun. 12, 2012,entitled “MANAGING A FLUID FLOW”, and assigned to the assignee of thepresent application. To the extent not repeated herein, the contents ofthis related patent application are hereby incorporated herein byreference.

FIELD

Embodiments relate generally to the field of medical infusion therapy.More particularly, embodiments relate to intravenous therapy.

BACKGROUND

In general, intravenous therapy is used to administer substancesdirectly into a vein of a patient. Many tubing systems used inadministration of intravenous or parenteral therapy employ a dripchamber. The drip chamber prevents air from entering the blood stream,causing air embolism. The drip chamber also allows for a flow rate ofthe administered substance to be estimated. Further, the drip chamberoffers a means to vent closed containers, such as bottles, therebypermitting filtered air to replace the fluid removed and thus avoidingthe formation of a vacuum that would inhibit flow. Some substances thatmay be infused intravenously include volume expanders, blood-basedproducts, blood substitutes, buffer solutions and medications.

Typically, the traditional IV infusion setup includes a pre-filled,sterile container (glass bottle, plastic bottle or plastic bag) offluid(s) with a tubular port that allows the attachment of an IV set'sdrip chamber “spike”. The IV set's drip chamber includes: a drip chamberorifice that allows the fluid to form drops of an approximate volume atslow flow rates, making it easy to see the flow rate (and also to avoidthe entrainment of air bubbles in the tubing); a long sterile tube witha variable restriction clamp to regulate or stop the flow of fluids; aconnector to attach to the vascular access device (VAD); connectors anda one-way check valve to allow “piggybacking” (Secondary mode infusionsetup) of another infusion set onto the same line, e.g., for adding adose of antibiotics to a continuous fluid drip. Further, the addition ofan infusion pump to the IV infusion setup allows for control over theflow rate and total fluid volume delivered to a patient.

In certain cases, where a change in flow rate and a total volumedelivered would not have serious consequences, flow is produced byelevating the container above the patient and employing gravity pressurein concert with manual adjustment of a clamp and visual monitoring ofthe rate of drop formation in the drip chamber to regulate the flowrate. Limitations exist with regards the administration of multiplesubstances using such a gravity mode intravenous therapy setup.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an example of a traditional Secondary mode infusion setup.

FIG. 2 shows an example Secondary mode infusion setup, including a dripchamber, in accordance with an embodiment.

FIG. 3 shows a cross-sectional view of the example drip chamber of FIG.2, in accordance with an embodiment.

FIG. 4 shows a cross-sectional view of the example drip chamber of FIG.2, in accordance with an embodiment.

FIG. 5 shows a flow diagram of an example method for managing a flow offluid within a flow control system, in accordance an embodiment.

FIG. 6 shows a flow diagram of an example method for manufacturing adrip chamber, in accordance with an embodiment.

FIG. 7 shows an example flow control system, in accordance with anembodiment.

FIG. 8A shows an example device, a tubing clamp coupled with a vacuumactivated catch, the tubing clamp being in the closed position, inaccordance with an embodiment.

FIG. 8B shows an example device, a tubing clamp coupled with a vacuumactivated catch, the tubing clamp being in the open position, inaccordance with an embodiment.

FIG. 9 shows an example flow control system, in accordance with anembodiment.

FIG. 10 shows a flow diagram of an example method for manufacturing adevice, in accordance with an embodiment.

FIG. 11 shows a block diagram of an example flow control system,including an example drip chamber, in accordance with an embodiment.

The drawings referred to in this description should not be understood asbeing drawn to scale unless specifically noted.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. While the subjectmatter will be described in conjunction with these embodiments, it willbe understood that they are not intended to limit the subject matter tothese embodiments. On the contrary, the subject matter described hereinis intended to cover alternatives, modifications and equivalents, whichmay be included within the spirit and scope. Furthermore, in thefollowing description, numerous specific details are set forth in orderto provide a thorough understanding of the subject matter. However, someembodiments may be practiced without these specific details. In otherinstances, well-known structures and components have not been describedin detail as not to unnecessarily obscure aspects of the subject matter.

Section One: Pressure Wave Damping Drip Chamber

Overview of Discussion

Herein, various embodiments of a drip chamber, a fluid control systemand methods for controlling the flow of fluid are described. Thedescription begins with a brief general discussion of a traditional flowcontrol system and drip chamber. This general discussion provides aframework of understanding for more particularized descriptions offeatures and concepts of operation associated with one or moreembodiments of the described fluid control technology.

Flow Control Systems with Respect to Drip Chambers

As discussed herein, traditional flow control systems are used to applyintravenous or intravascular (IV) therapy. IV therapy is theadministration of substances directly into a vascular system of apatient. Many systems of administration of IV therapy use a “dripchamber”. The drip chamber, in general, prevents air from entering theIV tubing and ultimately the blood stream (causing air embolism) andallows for an estimate of a flow rate of the medication administered.

Referring now to FIG. 1, an example of a traditional Secondary modeinfusion setup 100 is shown. Traditional Secondary mode infusion setup100 includes a Primary container 104 coupled with a Primary drip chamber108, and a Secondary container 136 (positioned at a location higher thanthe Primary container 104) coupled with a Secondary drip chamber 132.The Primary container hangs from the hanger 102, while the Secondarycontainer 136 hangs from the same line 138 from which the hanger 102 isattached. The Primary drip chamber 108 is coupled with a Primary fluidline 112, wherein the Primary fluid line 112 runs to a pump 120. Inbetween the Primary drip chamber 108 and the pump 120, a check valve 116is coupled with the Primary fluid line 112. Further, the Secondary dripchamber 132 is coupled with a Secondary fluid line 128, wherein theSecondary fluid line 128 also runs to the pump 120. In between theSecondary drip chamber 132 and the pump 120, a male luer 126 andneedle-free valve connection 124 is coupled with the Secondary fluidline 128. On the downstream side, or patient-side portion, of theadministration set of the pump 120 is a vascular access device (akacatheter, e.g. IV fluid line 122) or interconnecting plumbing such as anextension set or a needlefree valve.

When the Secondary fluid level 135 in the Secondary container 136 is ata level above the Primary fluid level 107, a hydrostatic pressuredifferential is created across the check valve 116 causing it to close,thereby preventing flow of the Primary fluid 106 from the Primarycontainer 104 to the pump 120 and significantly, preventing reverse flowof the Secondary fluid 134 into the Primary container 104. However, whenthe Secondary fluid level 135 decreases as fluid is withdrawn and/or ifthe Secondary container 136 is lowered such that the Secondary fluidlevel 134 is at about the same height as the Primary fluid level 107,the pressures directed at the inlet 114 and the outlet 118 of the checkvalve 116 approach equilibrium. Ideally, when the Primary side pressureon the check valve 116 becomes just slightly greater than the Secondaryside pressure on the check valve 116, the pump 120 will draw fluidsolely from the Primary container 104.

Even if the Secondary fluid level 135 is higher than the Primary fluidlevel 107, if the pump flow rate is in the range of 250 to 1000milliliters per hour, there may be pressure loss through a restrictionin the flow path of the Secondary container 136, such as due to theconnection between the male luer 126 and the needle-free valveconnection 124. Flow through a restriction (Of note, there may bemultiple restrictive elements such as a vent in the drip chamber whichhas become wetted, thereby increasing its resistance to flow.) causes apressure loss, thereby reducing the pressure applied on the check valve116 from the Secondary side. When there is just a slightly positivepressure across the check valve 116 from the Primary side, the checkvalve 116 will open, thereby allowing flow from the Primary container104 to occur intermittently with each pulse of flow aspirated by thepump. Thus, there may be concurrent flow from both the Primary andSecondary containers, 104 and 136, respectively, in some varyingproportion dependent on the flow rate, the restriction and the degree ofpulsatility of the pump's intake flow pattern.

When the Secondary fluid level 135 has lowered sufficiently in theSecondary container 136, the pressure of the Primary fluid 106 willremain consistently slightly higher than the pressure of the Secondaryfluid 134. The check valve 116 is continuously open allowing all thefluid to preferentially be drawn from the Primary container 104, whilethe Secondary fluid level 135 in the Secondary container 136 will remainfairly constant. Note that at this point, since there is no flow comingfrom the Secondary container 136, no pressure pulses are being producedvia the Secondary restriction, so the check valve 116 is held open bythe differential pressure between the Secondary container 136 and thePrimary container 104, only.

In the delivery of chemotherapy, clinicians frequently use thetraditional Secondary mode infusion setup 100. This is in part owing toits convenience and safety in the handling and transport of themedication and is in part due to the frequent need to infuse pre andpost medication fluids via the same IV catheter. While using thetraditional Secondary mode infusion setup 100 within an oncologyframework, several issues and problems become apparent. Firstly, largerand taller bags and bottles (containers) are used to hold a large volumeof medication. Secondly, much higher flow rates than the traditionalSecondary mode infusion setup 100 was originally designed for are used.Thirdly, the use of some needle-less (a.k.a. needle-free) valveconnectors may present somewhat higher flow restrictions in theSecondary pathway than the large bore metal needle/rubber port used whenthe traditional Secondary mode infusion setup 100 was developed.Fourthly, the length of hangers for lowering the Primary container 104may not be adequate to lower the Primary container sufficiently toassure adequate pressure differential in these demanding applications.

As the Secondary fluid 134 finishes delivery, the taller Secondarycontainer(s) 136 together with inadequate hanger length means that theelevation of the Secondary fluid 134 relative to the Primary fluid level107 will be lower than with smaller Secondary container(s). Without anadequate pressure difference of the Secondary side over the Primaryside, the Primary fluid 106 can begin flowing prematurely before theSecondary fluid 134 is completely delivered, due to the normal action ofthe check valve 116. This may result in delayed delivery completion ofthe Secondary fluid 134, since for each drop of the Primary fluid 106delivered, a drop of Secondary fluid 134 is NOT delivered. Thus, someamount of the Primary fluid 106 replaces some amount of the Secondaryfluid 134 as its level lowers, thereby causing the inadvertent delay inthe delivery completion of the Secondary fluid 134. Further, the checkvalve 116 located along the Primary fluid line 112 may transiently openprior to completion of the delivery of Secondary fluid 134 due topump-flow-induced transient drops in pressure, thereby producing acondition of concurrent flow in varying proportion from both the Primaryand Secondary containers, 104 and 136, respectively.

The intake flow from pumps is not entirely steady. In fact, in many pumpdesigns, the pump 120 draws fluid in at several times the mean outflowrate. When these rapid flows occur, they cause a pressure loss throughany restriction in the Secondary pathway such as at a needle-free valveconnection 124 or a blocked intake air vent 140. These transientpressure drops allow the check valve 116 to open very briefly, and thenclose. Thus, even if there was a suitable head height difference betweenthe Secondary fluid level 135 and the Primary fluid level 107, there maystill be inadequate pressure within the Primary fluid line 112 toprevent inadvertent partial flow from the Primary container 104 whilefluid remains to be delivered in the Secondary container 136. (In otherwords, and briefly, the restriction of the Secondary fluid line 128 istoo high and the pulsation of the intake of the pump 120 is too abrupt,causing the inadvertent partial flow from the Primary container 104while fluid remains to be delivered in the Secondary container 136.) Foroncology and other patients who similarly require a particular volume ofmedication to be administered within a precisely defined period of time,the delayed delivery completion of the Secondary fluid 134 from theSecondary container 136 may result in complications in schedulingsubsequent therapy and other clinical management difficulties for thehospital.

Embodiments incorporate a check valve placed uniquely within a dripchamber of a Primary delivery set, thereby overcoming many of theproblems besetting the traditional infusion setup 100. In oneembodiment, the drip chamber is used with IV therapy. However, whileembodiments are described within the context of IV therapy, it should beunderstood that the concepts described herein may be applied to adevice/integration within equipment other than for use in IV therapy.

Embodiments allow for taller containers, higher flow rates, Secondarypath connections having less than ideal low resistance and pumps havingless than ideal smooth intake flow to be used during IV therapy, whilestill preventing flow through the Primary fluid line when the Secondarycontainer is nearly empty (i.e. substantially empty). As noted earlier,when elevations of Primary and Secondary fluids are about equal, thecheck valve no longer is held closed and thus allows the Primary fluidto flow (intended). In practice, the Secondary level may have to be justa small amount lower than the Primary fluid due to the design of somecheck valves which requires a so called ‘cracking pressure’ to open.This is typically no more than one inch of water pressure (elevation).Embodiments provide for no flow coming from the Secondary container. Ifflow did come from the Secondary container, then the reduced Secondarypressure would quickly reopen the check valve, thereby drawing fluidtotally from the Primary container. More specifically, embodimentsmitigate the effect of pressure pulses that cause the check valve toopen intermittently before the Secondary fluid has been completelydelivered.

Moreover, in one embodiment, by having a (one-way) check valve placedabove the drip forming orifice and the pocket of air within the dripchamber (along with a controlled restriction in the drip chamberorifice), wherein the walls of the drip chamber provide a certain amountof elasticity, the likelihood that the pressure pulses from the infusionpump would cause an unwanted Primary fluid to replace desired Secondaryfluid prior to the delivery of the Secondary fluid is significantlyreduced. By placement of a check valve more remote (further upstream)from its typical placement near the connecting port, the inherentelasticity of the Primary tubing together with its own resistancetherein to a movement of fluid there through provide an additionalsource of damping of the effects of the pressure wave of the infusionpump. The walls of the drip chamber itself, along with the fluidresistance and fluid inertance within the drip forming orifice, damp thenegative pressure created by the pressure pulses from the infusion pump.By damping the negative pressure pulses created by the infusion pump'sintake flow pattern, the now steady reverse pressure across the checkvalve prevents the Primary fluid from moving through the check valve.

In one embodiment, the one-way check valve includes a bypass mechanism.The bypass mechanism allows the one-way check valve, in response to asignal, to open to allow Primary fluid to move through the one-way checkvalve in a direction that is reverse to the direction of the currentfluid flow from the container. This bypass mechanism enablespractitioners to expel excess IV fluid from the drip chamber back intothe container by inverting the drip chamber and gently squeezing it.This allows adjustment of the amount of fluid in the drip chamber topermit visualization of drops. It should be appreciated that alternateembodiments may include “bypass” mechanisms, other than the bypassmechanism described herein, that enable the release of fluid through afluid line. For example, but not limited to such, a channel parallel tothe check valve may be opened by a deformation of the fluid pathwayand/or by an activation of a lever (or similar device).

Thus, embodiments improve the accuracy of the Secondary Mode delivery ofsubstances by minimizing the unintended flow from a Primary containerwhile the Secondary fluid remains to be delivered. For example, fortime-critical Secondary applications, such as chemotherapy, where flowsare high (>300 ml/h), pressure loss through the Secondary pathway isexacerbated by the pulsatile intake flow of many pumps. Embodimentsmarkedly minimize the exposure of the check valve to these pulsatilepressures, thereby reducing unintended check valve opening withattendant flow from the Primary container prior to completion of theSecondary fluid administration.

Additionally, embodiments reduce the cost of the Primary set byintegrating components and reducing labor during its manufacture.Currently, one check valve is used in a significant percentage ofPrimary sets built. Assembly of these check valves into the finisheddelivery set adds steps and points for possible failure. By integratingthe check valve within the drip chamber, manufacturing steps areeliminated, resources are saved and reliability can be improved.

The following discussion will focus on example structures and exampleoperations, in accordance with embodiments. For clarity and ease ofexplanation of an example first drip chamber 206A (of FIG. 2), FIG. 2shows a Secondary mode infusion setup 200 (hereinafter, “infusion setup200”), in accordance with an embodiment. The drip chamber 206B of FIG. 3and the drip chamber 206C of FIG. 4 are enlarged views of first dripchamber 206A of FIG. 2, in accordance with an embodiment. The infusionsetup 200 shows the first container 204 (supported by hanger 202) andthe second container 230 hanging directly from the line 232. Further,the first and second containers, 204 and 230, respectively, in variousembodiments, may be used in a device/integration within equipment otherthan for use in IV therapy.

In one embodiment, the first container 204 is a Primary container, thefirst fluid line 214 is a Primary fluid line, the first fluid 234 is aPrimary fluid, the second container 230 is a Secondary container, thesecond drip chamber 228 is a Secondary drip chamber, the second fluidline 224 is a Secondary fluid line, the second fluid 236 is a Secondaryfluid, the first fluid flow is a Primary fluid flow, and the secondfluid flow is a Secondary fluid flow. Thus, the descriptions herein,with regards to FIGS. 1-6, using the terms “first” and “second” may beassociated with the delivery of Secondary medications (as is commonlyknown in the art), in one embodiment.

The first drip chamber 206A is coupled with and between the firstcontainer 204 and the infusion pump 216. The first fluid line 214couples the first drip chamber 206A with the infusion pump 216. Thefirst drip chamber 206A includes a spike 208, a drip forming orifice 212(providing a controlled restriction or “fluid resistance”) and a checkvalve 210 coupled with and between the spike 208 and the drip formingorifice 212.

As part of the infusion setup 200, a second drip chamber 228 is showncoupled with and between the second container 230 and the infusion pump216. Of note, the second drip chamber 228 does not include all of thefeatures of the first drip chamber 206A. The second fluid line 224couples the second drip chamber 228 with the infusion pump 216. In oneembodiment, attached to the second fluid line 224, between the seconddrip chamber 228 and the infusion pump 216, are a roller clamp 226, amale luer 222 and a needle-free valve connection 220. It should beappreciated that the roller clamp 226, the male luer 222 and theneedle-free valve connection 220 may be those that are commonly known inthe art. A patient IV fluid line 218 is coupled with the infusion pump216 and transports the fluid drawn from the first and/or secondcontainers, 204 and 230, respectively, to the patient.

The drip chamber 206B is shown as a block diagram in FIG. 3, inaccordance with an embodiment. The drip chamber 206B is an enlargementof the first drip chamber 206A of FIG. 2, the details of which will bediscussed herein. FIG. 4 shows a drip chamber 206C, a cross-sectionalview of the first drip chamber 206A (FIG. 2) and drip chamber 206B (FIG.3), in accordance with an embodiment, the details of which will bediscussed herein.

Referring now to FIG. 3, in one embodiment, the drip chamber 206Bincludes: a first end 312; a second end 314; a spike 208; a drip formingorifice 212 (providing a controlled restriction to flow); a check valve210; and an enclosing wall 318. The first end 312 includes an inlet 302.The second end 314 includes an outlet 316. The spike 208 is integrallycoupled with the first end 312. More specifically, the spike 208 iscoupled with the rest of the body of the drip chamber 206B such that theouter wall of the spike 208 is included as a portion of the “housing” ofthe drip chamber 206B at the first end 312.

In different embodiments, portions of the first end 312 includedifferent components, and portions of the second end 314 includedifferent components. For example, but not limited to such, in oneembodiment, the first end 312 of the drip chamber 206B includes thespike 208 and the check valve 210. However, in another embodiment, thefirst end 312 includes just the spike 208. Similarly, the second end 314of the drip chamber 206B includes the outlet 316, the air holdingportion 310 (discussed later) and the drip forming orifice 212, in oneembodiment. However, in another embodiment, the second end 314 of thedrip chamber 206B includes the outlet 316, the air holding portion 310,the drip forming orifice 212 and the check valve 210.

In one embodiment, the drip forming orifice 212 is coupled with thespike 208, with the check valve 210 disposed there between. An interiorflow passage 328 runs through and between the spike 208, check valve 210and drip forming orifice 212 (which also, in one embodiment, provides apath that includes a flow restriction). The first end 306 of theinterior flow passage 328 is positioned at the inlet 302 of the dripchamber 206B. The second end 322 of the interior flow passage 328 ispositioned at the intake side of the check valve 210. Connected to theoutlet of the check valve 210 is the lower section of the interior flowpassage 328, which also connects to the drip forming orifice 212.Further, the enclosing wall 318, which is coupled with the first end 312and the second end 314, houses within the spike 208, the check valve 210and the drip forming orifice 212.

In one embodiment, the check valve 210 is a one-way check valve. Again,of note, the check-valve is typically one-way by design. The one-waycheck valve allows a fluid to flow in a second direction 304 within theinterior flow passage 328, while stopping a fluid from flowing in afirst direction 320 within the interior flow passage 328. Referring nowto FIGS. 2 and 3, in one example, the fluid flowing in the seconddirection 304 is the first fluid 234 from the first container 204, andthe fluid attempting to flow in the first direction 320 is the secondfluid 236 from the second container 230. The fluid flowing in the seconddirection 304 is flowing in an opposite direction as the fluidattempting to flow in the first direction 320. Thus, the check valve 210allows the first fluid 234 to flow down to the first fluid line 214 tothe infusion pump 216, while stopping any fluid from flowing up throughthe check valve 210 and into the first container 204. This fluid that isstopped may be the first fluid 234 itself that has already traveled pastthe drip forming orifice 212, and/or it may be second fluid 236 havingbeen drawn into the drip chamber 206B.

Referring still to FIGS. 2 and 3, in one embodiment, the drip chamber206B includes a pressure damping elastic component. The pressure dampingelastic component includes an air holding portion 310 of the dripchamber 206B and at least a portion 308 of the enclosing wall 318 thatis elastic. It should be appreciated that the at least a portion 308 ofthe enclosing wall 318 that is elastic may be all of the enclosing wall318, or a portion less than an entirety of the enclosing wall 318. Theair holding portion 310 of the drip chamber 206B holds air. The airholding portion 310 and the at least a portion 308 of the enclosing wall318 that is elastic include an elasticity that damps a pressure pulsefrom the infusion pump 216. The infusion pump 216, as shown in FIG. 2,is fluidly coupled with the drip chamber 2068. It should be noted thatthe infusion pump 216 used with embodiments is an infusion pump that iscommonly known in the art to be used with IV therapy.

In one embodiment, the drip forming orifice 212 includes a flowresistance channel 324. The flow resistance channel 324 provides ahydraulic resistance to a fluid flowing from the outlet 316 to the inlet302. The term, “hydraulic resistance”, refers to the resistance to themovement of fluid through an area. For example, the flow resistancechannel 324 resists the movement of fluid through the drip formingorifice 212 from the infusion pump 216 side. This hydraulic resistanceinteracts with the pressure damping elastic component (the air holdingportion 310 and the portion 308 of the enclosing wall 318 that iselastic) to form a “damper” which attenuates pressure pulses originatingdownstream in the second fluid line 224 due to the infusion pump's 216intake flow through a restriction in the second fluid line 224. Thus,the air holding portion 310 and the portion 308 of the enclosing wall318 that is elastic (i.e., the pressure damping elastic componentdescribed herein) contribute additively to the total compliance of thedrip chamber. That compliance, in turn, interacts with the flowresistance channel 324 to form what is called the ‘damping’ effect.

In one embodiment, the drip chamber 206B includes a pressure damper thatshields the check valve 210 from a negative transient pressure. Thenegative transient pressure is that pressure caused by the pulsatingpump, thereby drawing fluid towards the infusion pump 216 through anyresistance in the fluid pathway (e.g., Secondary fluid pathway). If thecheck valve 210 were to receive the full effects of the pressure causedby the infusion pump 216 that is pulsating, the check valve 210 wouldopen transiently, thereby allowing bursts of fluid to rapidly dripthrough the drip forming orifice 212 and ultimately through the dripchamber 206B.

The pressure damper includes the combination of the flow resistancechannel 324 and the pressure damping elastic component described herein.The net damping effect, as measured by the highest frequency which ispassed without attenuation, is inversely proportional to the product ofthe resistance and the compliance of the pressure damping elasticcomponent (including the air holding portion 310 and the at least aportion 308 of the enclosing wall 318 having an elasticity). Thus, it isthe two aspects working together that result in the effective damping ofunwanted pressure waves. Additionally, aggressively increasing at leastone of the following serves to attenuate pulses that originate in theinfusion pump flow passing through the restriction of the Secondarypathway: the resistance to the movement of fluid through an area; andthe compliance of the air holding portion 310 and the enclosing wall 318having an elasticity.

Therefore, the damping provided by the flow resistance channel 324together with the pressure damping elastic component, including elasticelements therein, protects the check valve 210 from exposure tonegative—going transient pressure which could cause the check valve 210to temporarily and prematurely open. This premature and intermittentopening may cause the unintended partial flow of the first fluid 234while the second fluid 236 remains to be delivered.

Under some circumstances, there may be excess fluid in a drip chamber.This reduces both the ability of the clinician to visualize drops formonitoring, as well as reduces the elasticity, described above, that isuseful in damping unwanted pressure waves. In one embodiment, the checkvalve 210 of the drip chamber 206B includes a bypass mechanism 326. Thebypass mechanism 326 opens the check valve 210 in response to receivingan opening trigger, thereby releasing a fluid flowing in the firstdirection 320 through the check valve 210 from the outlet 316 to theinlet 302. In one embodiment, the opening trigger is a thresholdpressure of the fluid flowing in the first direction 320 from the outlet316 to the inlet 302. The threshold pressure refers to that pressurewhich is needed to cause a portion of the check valve 210 to open to letthe fluid flow through. In one embodiment, the threshold pressure neededwould be between 4 and 8 psi. For example, the threshold pressure may beprovided by the nurse's fingers squeezing the body of the first dripchamber 206A to remove excess fluid out of the first drip chamber 206Aand restore the normal amount of air. Of note, the first drip chamber206A and bag must be inverted so that when the wall of the first dripchamber 206A is released from squeezing, it will draw air, and notfluid, from the bag.

In another embodiment, the opening trigger is a threshold force appliedagainst the check valve 210, thereby causing the check valve 210 todeform from a first shape to a second shape. For example, a practitionermay deform the housing or activate an attached element that wouldtrigger the bypass mechanism 326 to cause the check valve 210 to open toallow the fluid to flow there through. In one embodiment, the bypassmechanism 326 is a deformation characteristic of a component within thecheck valve 210 that changes shape, such as the shape of a bell curvethat faces one direction to the shape of a bell curve that faces anopposite direction. The shape change leaves an opening within theinterior flow passage 328 that allows for fluid to flow there through.

With reference to FIG. 4, an example drip chamber 206C is shown,including: a check valve 210 coupled with and between a spike 208 and adrip forming orifice 212. The spike 208 includes at least a portion ofthe interior flow passage 328 and an air passageway 412. In anotherembodiment, the spike 208 includes the interior flow passage 328 withoutthe air passageway 412. For example, a drip chamber may not have a ventpath, such as with bags whose walls collapse as the fluid is withdrawn,thus not requiring a path for replacement air to enter. The inlet 302 isat one end of the interior flow passage 328. An enlarged view 410 of thecheck valve 210 is also shown. It can be seen that the fluid flowsthrough the portion of the interior flow passage 328 of the check valve210, thereby flowing around an obstruction 408 in the middle of thecheck valve 210. It should be noted that a check valve that is known inthe art may be used as part of some embodiments described herein. In oneembodiment, the check valve includes the bypass mechanism 326, asdescribed herein.

FIG. 4 also shows a drip forming orifice 212, along with a drip 402 offluid falling from an end of the drip forming orifice 212. Further, theenclosing wall 318 couples with the first and second end, 312 and 314,respectively, of the drip chamber 206C, and houses within the spike 208,check valve 210 and drip forming orifice 212. Also shown is the pressuredamping elastic component 406 that includes the air holding portion 310and at least the portion 308 of the enclosing wall 318 that includes anelasticity. The fluid drips into the air holding portion 310 to form avolume of fluid 404. A portion of that volume of fluid 404 may thencontinue moving through components (such as the first fluid line 214,the infusion pump 216 and the patient IV fluid line 218) coupled withthe drip chamber 206C to reach the patient.

With reference now to FIGS. 3 and 4, a device for managing fluid flowmay be described, according to one embodiment. The device includes: adrip chamber 206B. The drip chamber 206B of the device includes, in oneembodiment: an inlet 302; an outlet 316; and a check valve 210positioned between the inlet 302 and the outlet 316. The check valve 210manages fluid flowing between the inlet 302 and the outlet 316. In oneembodiment, the drip chamber 206B further includes the flow resistancechannel 324.

The example device further includes, in one embodiment, the enclosingwall 318 that couples the first end 312 with the second end 314. Theenclosing wall 318 houses within at least the spike 208, the check valve210 and the drip forming orifice 212. An additional embodiment of thedevice includes the pressure damping elastic component described herein.In yet another example embodiment, the device includes the pressuredamper described herein.

In one example device, the check valve is the one-way check valvedescribed herein. Further, in yet another embodiment, the one-way checkvalve includes the bypass mechanism described herein.

FIG. 5 is a flow diagram of an example method 500 for managing a flow offluid within a flow control system, in accordance with embodiments.

Referring now to FIGS. 2-5, at 505 and as described herein, in oneembodiment, the method 500 includes receiving 505 a fluid flow, thereceiving occurring at a drip forming orifice 212 of a drip chamber206C. The fluid flow occurs at a first rate in a first direction 320. At510 and as described herein, in one embodiment, the drip forming orifice212 resists the fluid flow. At 515 and as described herein, in oneembodiment, the check valve 210 stops the fluid flow. The check valve210 is coupled with and positioned between the spike 208 and the dripforming orifice 212. The spike 208 is integrally coupled with the firstend 312 of the drip chamber 206C.

At 520 and as described herein, in one embodiment at least a portion 308of an effect of a pressure pulse formed by the infusion pump 216 isdamped. The infusion pump 216 is fluidly coupled with the drip chamber206C. The damping 520 includes at least one of: in response to receivingthe pressure pulse from the infusion pump 216, elastically expanding anair holding portion 310 and at least a portion 308 of the enclosing wall318 of the drip chamber 206C; and in response to receiving the pressurepulses from the infusion pump 216, providing a hydraulic resistance tothe fluid flow from an outlet of a second end of the drip chamber 206Cto an inlet of a first end of the drip chamber 206C. Of note and asdescribed herein, in one embodiment, the damping is produced not just bythe pressure damping elastic component 406 and not just by the flowresistance channel 324, but rather by the combined effect of thepressure damping elastic component 406 and the flow resistance channel324.

At 525 and as described herein, in one embodiment at least a portion 308of an effect of a pressure pulse formed by the infusion pump 216 isdamped. The infusion pump 216 is fluidly coupled with the drip chamber206C via a tubing. The tubing elastically expands in response to thereceiving of the pressure pulse from the infusion pump and provides aresistance within to the movement of the fluid there through.

At 530 and as described herein, in one embodiment a volume of fluid 404that is stopped at the check valve 210 is released. The releasing ofthis volume of fluid 404 includes: receiving a check valve openingtrigger; and in response to the receiving of the check valve openingtrigger, opening the check valve 210. In one embodiment, the receivingof the check valve opening trigger includes the receiving of a thresholdpressure that is applied by a fluid flowing in a first direction 320. Inanother embodiment, the receiving of the check valve opening triggerincludes the receiving of a threshold force applied against the checkvalve 210, wherein the threshold force applied against the check valve210 deforms the check valve 210 from a first shape to a second shape.

FIG. 6 is a flow diagram of a method 600 for manufacturing a dripchamber, such as drip chamber 206C of FIG. 4, in accordance with anembodiment.

Referring now to FIGS. 2-4 and 6, at 605 and as described herein, in oneembodiment, the method 600 includes providing 605 a spike 208 integrallycoupled with an enclosing wall 318 of the drip chamber 206C. At 610 andas described herein, in one embodiment, the drip forming orifice 212 isprovided. At 615 and as described herein, in one embodiment, the checkvalve 210 is coupled with and between the spike 208 and the drip formingorifice 212. In one embodiment and as described herein, the check valve210 is a one-way check valve. In another embodiment and as describedherein, the check valve 210 includes the bypass mechanism 326.

Further, and as described herein, in one embodiment, the enclosing wall318 is integrally coupled with the spike 208. The enclosing wall 318includes an inlet 302 and an outlet 316 and encloses at least the spike208, the check valve 210, the drip forming orifice 212 and the interiorflow passage 328 (that extends through the spike 208, the check valve210 and the drip forming orifice 212 as well as between the inlet 302and the outlet 316).

At 620 and as described herein, in one embodiment, the pressure dampingelastic component 406 is integrally coupled with the enclosing wall 318.The pressure damping elastic component 406 includes the air holdingportion 310 of the drip chamber 206C and at least a portion of theenclosing wall 318 of the drip chamber 206C that is elastic, as isdescribed herein.

At 625 and as described herein, in one embodiment, the check valve 210is coupled with the pressure damper. The pressure damper shields thecheck valve 210 from a negative transient pressure. The pressure damperincludes: the flow resistance channel 324 and the pressure dampingelastic component 406 that is described herein.

Section Two: Vacuum Activated Catch for Managing a Fluid Flow

Herein, various embodiments of a device for controlling fluid flow, aflow control system and a method of manufacturing the device aredescribed. The description begins with a continuation of the briefgeneral discussion, in Section One regarding the example Drip Chamberabove, of the traditional flow control system and methods for deliveryof Secondary medications. This general discussion provides a frameworkof understanding for more particularized descriptions of features andconcepts of operation associated with one or more embodiments of thedescribed device and flow control system.

Flow Control Systems with Respect to Managing Fluid Flow

Referring to FIG. 1, traditional methods for delivery of Secondarymedications include employing the check valve 116 in the Primary setwhile lowering the Primary container 104 with a hanger 102 to create aback pressure against the check valve 116, thus keeping it closed untilthe Secondary fluid 134 has been delivered. This requires, but does notalways achieve, a very low flow resistance in the Secondary pathway.When high flow rates are involved and/or the resistance of the Secondarypathway is not sufficiently low, or when there is insufficient elevationdifference between the Primary and Secondary fluids, 106 and 134,respectively, some Primary fluid 106 will flow when only the Secondaryfluid 134 is intended to flow. This condition is referred to as“sympathetic flow”. This results in the delayed completion of theSecondary fluid 134. In other words, the pressure lost through excessresistance in the Secondary pathway effectively reduces the pressuredifferential across the check valve 116. This allows intermittent flowof the Primary fluid 106 to occur even though there may still besignificant fluid left in the Secondary container 136.

The traditional use of the check valve together with elevationdifferential has the following inherent weaknesses: it requires themanual lowering of the Primary container 104; uncertainty exists for theoperator regarding the needed elevation with regards to lowering thePrimary container 104; the resistance to the flow in the Secondary fluidline 128 may vary from setup to setup and may cause unintended flow fromthe Primary container 104, thereby delaying the completion of thedelivery of the Secondary fluid 134; air may be entrained when thePrimary container 104 is lowered below the Primary port entrance; andPrimary infusion setups used bear the cost of manufacturing the checkvalve 116, even though only a small percentage of the Primary infusionsetups are used for Secondary delivery of medication (and thus use thecheck valve 116).

In accordance with various embodiments, an example flow control systemincludes a device for controlling fluid flow and a sealable componentwhich automatically stops flow once fluid in the container is depleted(such as, but not limited to, a ball float valve) positioned within adrip chamber. The device includes a tubing clamp coupled with a vacuumactivated catch. When the tubing clamp is secured in a closed positionby the vacuum activated catch, a Primary fluid line is pinched closed.When the vacuum activated catch releases the tubing clamp to an openposition, the first fluid line is also released into an open position.The vacuum activated catch is also coupled with the Secondary containervia a Secondary fluid line. In between the Secondary container and thevacuum activated catch is a check valve. This check valve preventsreverse flow into the Secondary container when the tubing clamp is open.

Further, in embodiments, there is no need for the Primary container tobe lowered, which simplifies the work of a caregiver, thus removing asignificant source of error.

The sealable component is coupled with the Secondary container and stopsthe flow of the Secondary fluid when the Secondary container empties tothe drip chamber. When the sealable component seals shut, therebyclosing an interior flow passage within the drip chamber, the pump'sintake draws a vacuum in the Secondary fluid pathway. This vacuumdeforms a membrane in the vacuum activated catch that is coupled withthe Secondary fluid line, which then releases and opens the tubingclamp, thereby opening the Primary fluid line and allowing the Primaryfluid flow to commence there through.

Embodiments eliminate the need for a costly check valve to be placed inevery Primary infusion setup. Further, embodiments help to ensureon-time Secondary delivery of fluids. Moreover, the need for a hangerand/or to reposition containers is removed. Additionally, the device mayother forms of “vacuum activated” clamps or valves, such as, but notlimited to, using a lever arm to minimize the force needed to lock andrelease the clamping of a Primary fluid line.

The following discussion will focus on example structures and operationsof embodiments.

FIG. 7 shows a tubing clamp 706 coupled with a vacuum activated catch710, within a flow control system 700, in accordance with an embodiment.In embodiments, the flow control system 700 includes: a tubing clamp706; a vacuum activated catch 710 retainably coupled with the tubingclamp 706 and a second fluid line 714; a second drip chamber 724 coupledwith and between the second container 726 and the second fluid line 714;and an infusion pump 728 coupled with the first and second fluid lines,704 and 714, respectively. Additionally, in one embodiment, a one-waycheck valve 729 is shown in the second tubing pathway. This one-waycheck valve 729 prevents flow from the first container 702 when thetubing clamp 706 is open. In one embodiment, the one-way check valve 729is incorporated within the design of the device 800A/800B (of FIGS. 8Aand 8B, respectively), which includes the tubing clamp 706 and thevacuum activated catch 710. In another embodiment, the one-way checkvalve 729 is a conventional component positioned separately from thedevice 800A/800B.

In one embodiment, the first container 702 is a Primary container, thefirst fluid line 704 is a Primary fluid line, the first fluid 730 is aPrimary fluid, the second container 726 is a Secondary container, thesecond drip chamber 724 is a Secondary drip chamber, the second fluidline 714 is a Secondary fluid line, the second fluid 732 is a Secondaryfluid, the first fluid level 734 is a Primary fluid level, the secondfluid level 736 is a Secondary fluid level, the first fluid flow is aPrimary fluid flow, and the second fluid flow is a Secondary fluid flow.Thus, the descriptions herein, with regards to FIGS. 7-10, using theterms “first” and “second” may be associated with the delivery ofSecondary medications, in one embodiment.

FIG. 8A shows a device 800A, including a tubing clamp 706 (of FIG. 2)coupled with a vacuum activated catch 710. Referring to FIGS. 7 and 8A,in one embodiment, the tubing clamp 706 includes a first arm 816 and asecond arm 804 that is coupled with the first arm 816 via a connector818. In one embodiment, the connector 818 is flexible. Thus, in oneembodiment, the connector 818 and the first arm 816 and second arm 804to which it is attached are made of one piece. In another embodiment,the combination of the first arm 816 and the second arm 804 to which itis attached is made of at least two pieces that are manufactured toappear to be a single piece. In yet another embodiment, the connector818 to which the first arm 816 and the second arm 804 is attached is ahinge-like component such that portions of the hinge-like component openand close, thereby opening and closing the first arm 816 and the secondarm 804. In one example, connector 818 is an axle about which first arm816 and second arm 804 of the tubing clamp 706 pivot. Further, in oneembodiment, a spring is used to assure that when the tubing clamp 706 isopened, and the first arm 816 and the second arm 804 swing away. Inanother embodiment, the wall itself of the tubing clamp 706 providessufficient force to cause a desired opening of the first arm 816 and thesecond arm 804.

Further, in one embodiment, the second arm 804 is attached to a hookedend 810. For example, in one embodiment, the second arm 804 and thehooked end 810 are a single piece. However, in another embodiment, thecombination of the second arm 804 and the hooked end 810 to which thesecond arm 804 is attached is made of at least two pieces that aremanufactured to appear to be a single piece. Of note, it should beappreciated that the first arm 816, the clamping mechanism 802, thesecond arm 804 and the hooked end 810 may be a single piece or multiplepieces attached to each other, or any combination thereof.

Moreover, the first arm 816 and the second arm 804, in one embodiment,are long, slender beams. However, it should be appreciated that theshape and length of the first arm 816 and the second arm 804 may be anyshape and length such that the first arm 816 articulates with theholding notch 822 of the vacuum activated catch 710, thereby holding itin place.

Additionally and as will be discussed below in more detail, a firstattachment portion 812 and a second attachment portion 806 of the vacuumactivated catch 710 are coupled with the hook end 810 of the tubingclamp 706 such that a portion of the first arm of the tubing clamp 706may be held in place by one or more notches (such as but not limited toholding notch 822) in the vacuum activated catch 710. Of note, FIG. 8Aalso shows section AA, an end view of a circular shaped deformableelement 824, which is one example of a vacuum activated catch 710. Asseen, the circular shaped deformable element 824 includes the holdingnotch 822. The arrow pointing from the first attachment portion 812 tothe circular shaped deformable element 824 shows an attachment point at826. This represents where the first attachment portion 812 attaches tothe vacuum activated catch 710.

Referring still to FIGS. 7 and 8A, the tubing clamp 706 includes theclamping mechanism 802 that holds closed the first fluid line 704 whilea second fluid 732 flows along the second fluid line 714 from the secondcontainer 726. The first fluid line 704 delivers a flow of a firstfluid. The direction 712 of the flow of the second fluid 732 is from thesecond container 726 towards the infusion pump 728. The tubing clamp 706is in the closed position, in accordance with an embodiment.

The second drip chamber 724 includes a sealable component 722 that sealsclosed an interior flow passage 708 within the second drip chamber 724when the second container 726 is empty (or nearly empty [i.e.substantially empty]), thereby obstructing the flow of the second fluid732. In one embodiment, the sealable component 722 is a ball floatvalve. The ball float valve includes a ball 720 and a base 716, whereinwhen the second container 726 is empty (or nearly empty [i.e.substantially empty]), the ball 720 sets within the base 716, therebysealing the interior flow passage 708 within the second drip chamber724, such that the ball 720 prevents whatever small amounts of fluidthat are left, if any, within the second drip chamber 724 and/or thesecond container 726 from flowing through to the second fluid line 714.Of note, there can be some fluid left in the second container 726 sincesome bags (e.g., second container 726) have ‘side lobes’ where fluid maysequester and thus not flow into the spike, the drip orifice, andfinally the drip chamber (e.g., second drip chamber 724). However, theactivation of the ‘sealable’ element occurs when no further fluid isentering the second drip chamber 724 while the pump draws fluid out ofit. This is true whether the ‘ball float’ design, the filter, or anyother are employed.

For example and referring to FIG. 7, after the spike of the second dripchamber 724 is placed in the second container 726, fluid flows into thesecond drip chamber 724. The ball 720 has buoyancy that causes it tofloat on the volume of fluid 718 that fills a portion of the second dripchamber 724. When the second container 726 is emptied (or nearly empty[i.e. substantially empty]) and all (or nearly all) of the fluid hasexited the second drip chamber 724 through the interior flow passage 708into the second fluid line 714, the ball 720 sets into the base 716,thus sealing the portion of the interior flow passage 708 within thesecond drip chamber 724.

FIG. 9 shows a tubing clamp 706 coupled with a vacuum activated catch710, within a flow control system 900, in accordance with an embodiment.FIG. 9 also shows the ball 720 set into the base 716, as a result of thesecond container 726 being empty (or nearly empty [i.e. substantiallyempty]), and/or the infusion pump 728 drawing a vacuum through thesecond fluid line 714, thus pulling the ball 720 into the base 716.

Of note, the interior flow passage 708 is shown, in both FIGS. 7 and 9,as a dotted line from and through the second drip chamber 724 and thesecond fluid line 714. When the second container 726 is emptied (ornearly emptied), there is no longer any fluid and/or enough fluid tosupport a floating ball 720 such that the interior flow passage 708 iskept open. The ball 720 then sets in the base 716. The infusion pump728, in operation, draws a vacuum within the second fluid line 714 andaway from the second drip chamber 724. The displacement of the fluid bythe pump creates a negative pressure within the second fluid line 714,resulting in the deformation of the vacuum activated catch 710. Forexample, the vacuum activated catch 710 may pop inwards, releasing thefirst attachment portion 812, as shown in FIGS. 8B and 9, in response tothe negative transient pressure. Since the vacuum activated catch 710 isconstructed of a movable element, the vacuum activated catch 710 has theability to change shapes when receiving a pressure that overcomes thematerial's inherent characteristics causing stiffness. The inwarddeformation will cause a portion of the tubing clamp 706 to be released,as will be explained herein. The movable element may be, but is notlimited to, any of the following: a deformable membrane; a piston; arolling hat seal; and any structure capable of being displaced by thevacuum established by the closure of the second fluid path and continuedintake of fluid by the infusion pump 728.

In another embodiment, the sealable component 722 is a filter (not shownin the Figures). For example, but not limited to such, in one embodimentthe filter has a diameter of 0.22 micron. The filter is placed in thebase of the second drip chamber 724. When air is on one side and fluidis on the other side of the filter, a meniscus, having a bubble pointpressure, is created. The bubble point pressure blocks air from flowingthrough the filter. The bubble point pressure increases in inverseproportion to the filter's diaphragm diameter. In other words, thefilter produces a bubble point pressure that is sufficient to activatethe movable element, thereby releasing the vacuum activated catch 710that is closing the first tubing.

FIG. 8B shows a device 800B, the tubing clamp 706 (of FIG. 7) coupledwith the vacuum activated catch 710. The tubing clamp 706 is in an openposition, in accordance with an embodiment. Referring now to FIGS. 8Aand 8B, the vacuum activated catch 710 includes a movable element thatis coupled with the tubing clamp 706. The movable element changes from afirst shape 808 to a second shape 820 upon receipt of a deforming vacuumpressure. When the movable element is in the first shape 808, the vacuumactivated catch 710 retains the tubing clamp 706 in a closed position.When the movable element is in the second shape 820, the vacuumactivated catch 710 releases the tubing clamp 706 into an open position,thereby allowing the flow of the first fluid 730 to commence within thefirst fluid line 704.

In one embodiment, and as described herein, a portion of the first arm816 of the tubing clamp 706 is releasably secured by the holding notch822 of the vacuum activated catch 710. (Again, it should be noted thatthe vacuum activated catch 710 may include more than one holding notch822.) For example, in one embodiment, the movable element has a holdingnotch 822 for holding the first arm 816 of the tubing clamp 706 inplace. In one embodiment, the movable element is of a shape that iscapable of changing from a first shape 808 to a second shape 820 (ofFIG. 8B) upon applied vacuum (a positive pressure) and/or force suchthat the first arm 816 of the tubing clamp 706 is released from theholding notch 822 of the vacuum activated catch 710, such as, but notlimited to, a cup shape, a disk shape, or a combination thereof.

Referring to FIG. 8A, it can be seen that in one embodiment, when themovable element of the vacuum activated catch 710 is in a first shape808, the vacuum activated catch 710 secures closed the first arm 816 ofthe tubing clamp 706 such that the first fluid line 704 is pinchedclosed.

Referring now to FIG. 8B, the tubing clamp 706 is in an open position.In one embodiment, the movable element of the vacuum activated catch 710releases the first arm 816 of the tubing clamp 706 while the movableelement is in the second shape 820, such that the first fluid line 704opens. It should be appreciated that the second shape 820 of the movableelement may be any shape that allows the first arm 816 to be releasedfrom its secured position such that the first fluid line 704 is thenopened. The second shape 820 may be that shape which is different fromthe first shape 808, such that the end of the first arm 816 can nolonger be secured in a closed position. For example, but not limited tosuch, if the first shape is a bell curve, then the second shape 820 maybe flat.

The infusion pump 728 draws a vacuum in the second fluid line 714,thereby creating the deforming force (the pressure is a negative value)when the second container 726 is substantially empty (i.e. empty ornearly empty). In one embodiment, the deforming pressure is a negativepressure caused by the drawing of the vacuum. More specifically, theinfusion pump 728 withdraws fluid from the blocked tubing, therebydrawing or producing a vacuum. In one embodiment, the infusion pump 728has a pressure sensor.

Further, as can be seen, once the movable element pops in and releasesthe first arm 816 of the tubing clamp 706, thus opening the first fluidline 704, the first fluid 730 commences flowing in the direction 902from the first container 702 towards the infusion pump 728. Since thefirst fluid level 734 is now higher than fluid in the second container726, the one-way check valve 729 is forced closed so that only the fluidfrom the first container 702 flows only to the infusion pump 728.

With reference to FIGS. 7-9, an embodiment of a device may be described.In one embodiment, a device includes a tubing clamp 706 and a vacuumactivated catch 710. The tubing clamp 706, according to one embodiment,holds closed the first fluid line 704 while the second fluid 732 flowsalong a second fluid line 714 from the second container 726, wherein thefirst fluid line 704 delivers a flow of first fluid 730. The vacuumactivated catch 710, according to one embodiment, is coupled with thesecond fluid line 714 and is releasably secured as described herein, bythe tubing clamp 706. The term, “releasably secured”, refers to theability of the tubing clamp 706 to release, as well as hold in place, aportion of the vacuum activated catch 710. Upon receipt of a deformingforce, the catch 710 opens and allows the flow of the first fluid 730within the first fluid line 704. In one embodiment, the deforming forceis due to a vacuum caused by the infusion pump 728 that is coupled withthe second fluid line 714, wherein the infusion pump 728 draws a vacuumduring operation by aspirating fluid from the tubing.

In one embodiment, the tubing clamp 706 includes the clamping mechanism802 described herein. In yet another embodiment, the vacuum activatedcatch 706 includes the movable element described herein.

A further embodiment of the tubing clamp 706 of the example deviceincludes a first arm 816 and a second arm 804 coupled with the first arm816 via the connector 818, wherein the connector 818 is flexible.

FIG. 10 is a flow diagram of an example method 1000 for manufacturing adevice, in accordance with embodiments.

Referring now to FIGS. 7-10, at 1005 and as described herein, in oneembodiment, the method 1000 includes providing a tubing clamp 706,wherein the tubing clamp 706 includes a clamping mechanism 802configured for holding closed a first fluid line 704 while the secondfluid 732 flows along a second fluid line 714 from a second container726. The first fluid line 704 delivers a flow of a first fluid 730.Further, in one embodiment, the providing 1005 of the tubing clamp 706includes providing a first arm 816 and a second arm 804 of the tubingclamp 706, and coupling the first arm 816 and the second arm 804 withthe connector 818, wherein the connector 818 is flexible.

At 1010 and as described herein, in one embodiment the method 1000includes coupling a vacuum activated catch 710 with the tubing clamp706, wherein the vacuum activated catch 710 includes a movable elementcoupled with the tubing clamp 706 and configured for changing from afirst shape 808 to a second shape 820 upon receipt of a deforming force.When the movable element is in the first shape 808, the vacuum activatedcatch 710 retains the tubing clamp 706 in a closed position. When themovable element is in the second shape 820, the vacuum activated catch710 releases the tubing clamp 706 into an open position, therebyallowing the flow of the first fluid 730 to commence within the firstfluid line 704. Further, in one embodiment, the coupling 1010 of thevacuum activated catch 710 includes coupling a first attachment portion812 and a second attachment portion 806 of the movable element with ahooked end 810 of the second arm 804 of the tubing clamp 706.

At 1015 and as described herein, in one embodiment the method 1000includes disposing at least one latching element on the movable element,such that the movable element is enabled to secure the tubing clamp 706in a closed position. For example and with reference to FIG. 8A, thefirst shape 808 includes a concave portion that receives an end of thefirst arm 816. The fitting together of the concave portion and the endof the first arm 816 shows the function of the at least one latchingelement of the first shape 808, that of the concave portion. In otherwords, areas may be disposed on the movable element that are capable ofreceiving one or more portions of the first arm 816 such that themovable element secures and retains the first arm 816 in a position thatallows the first fluid line 704 to be and remain pinched closed, untilreleased.

Further, the vacuum activated catch 710 functions in a bi-stable mode.That is, once it ‘switches’ to the released position, it no longerrequires vacuum force to remain in that position. Thus, as soon as theclamp opens, the vacuum disappears. One embodiment provides a means forthe operator to place the vacuum operated catch 710 back into thelatching position. For example, but not limited to such example, a tabis used that enables the vacuum activated catch 710 to be manuallypulled out and placed back into the latching position. In anotherembodiment, a pushing element from within the fluid path is used, thepushing element allowing the vacuum activated catch 710 to be placedback into the latching position.

Section Three: an Example Drip Chamber Integrated within an Example FlowControl System

Herein, various embodiments of a flow control system integrated with adrip chamber are described. The description below describes theintegration of the example drip chamber discussed in Section One abovewith the example flow control system discussed in Section Two above.

FIG. 11 shows a tubing clamp 706 coupled with a vacuum activated catch710, within a flow control system 1100, in accordance with anembodiment. In embodiments, the flow control system 1100 includes: thetubing clamp 706; the vacuum activated catch 710 retainably coupled withthe tubing clamp 706 and the second fluid line 714; the first dripchamber 206A (of FIG. 2) coupled with and between the second container726 and the second fluid line 714; and the infusion pump 728 coupledwith the first and second fluid lines, 704 and 714, respectively. FIG.11 further shows, in accordance with various embodiments: the firstcontainer 702

In one embodiment, the first container 702 is a Primary container, thefirst fluid line 704 is a Primary fluid line, the first fluid 730 is aPrimary fluid, the second container 726 is a Secondary container, thefirst drip chamber 206A is a Secondary drip chamber, the second fluidline 714 is a Secondary fluid line, the second fluid 732 is a Secondaryfluid, the first fluid level 734 is a Primary fluid level, the secondfluid level 736 is a Secondary fluid level, the first fluid flow is aPrimary fluid flow, and the second fluid flow is a Secondary fluid flow.Thus, the descriptions herein, with regards to FIGS. 7-11, using theterms “first” and “second” may be associated with the delivery ofSecondary medications, in one embodiment.

In one embodiment and as described herein, the tubing clamp 706 includesthe clamping mechanism 802 (of FIGS. 8A and 8B) that holds closed thefirst fluid line 704 while the second fluid 732 flows along the secondfluid line 714 from the second container 726. The first fluid line 704is coupled with the first container 702 and delivers a flow of the firstfluid 730.

Referring to FIG. 3, the example drip chamber 206B (a cross-sectionalview of the example first drip chamber 206A) includes in one embodimentand as described herein the following: the first end 312 having an inlet302; the second end 314 having an outlet 316; a spike 208 integrallycoupled with the first end 312; a drip forming orifice 212 coupled withthe spike 208; a check valve 210 disposed between and coupled with thespike 208 and the drip forming orifice 212; the enclosing wall 318coupling the first end 312 and the second end 314; and the sealablecomponent 722 (of FIG. 7).

Referring now to FIGS. 3 and 11, in one embodiment and as describedherein, the check valve 210 manages the fluid flowing between the inlet302 and the outlet 316 through the interior flow passage 328 thatextends at least through the spike 208. In one embodiment, the enclosingwall 318 houses within at least the spike 208, the check valve 210 andthe drip forming orifice 212. In one embodiment and as described herein,the sealable component 722 (including the ball 720 and the base 716 thatare intermittently separated by the volume of fluid 718; see FIGS. 7 and9) seals closed the interior flow passage 328 within the drip chamber206B when the second container 726 is substantially empty, therebyobstructing the flow of the second fluid 732.

The vacuum activated catch 710 includes a movable element coupled withthe tubing clamp 706, according to one embodiment and as describedherein. The movable element changes from a first shape (e.g., firstshape 808 of FIG. 8A) to a second shape (e.g., second shape 820 of FIG.8B) upon receipt of a deforming force, wherein when the movable elementis in the first shape, the vacuum activated catch 710 retains the tubingclamp 706 in a closed position. When the movable element is in thesecond shape, the vacuum activated catch 710 releases the tubing clamp706 in an open position, thereby allowing the flow of the first fluid730 to commence within the first fluid line 704, according to oneembodiment.

In another embodiment and as described herein, the infusion pump 728draws a vacuum in the second fluid line 714, thereby creating thedeforming force when the second container 726 is substantially empty.

The check valve 210 incorporated in the Secondary set prevents thereverse flow of the Primary fluid (i.e., first fluid 730) into theSecondary container (i.e., the second container 726). For example, thehydrostatic pressure of the fluid in the Primary fluid line will begreater than that in the Secondary fluid line at the moment the tubingclamp 706 opens on the Primary fluid line. Additionally, the check valve210 facilitates keeping the ball 720 from moving away from the base 716(and thus re-opening), thereby preventing the backward flow of thePrimary fluid flow into an empty Secondary container (i.e., secondcontainer 726). While employing the sealable component 722 (includingthe ball 720 and base 716) and without the check valve's 210 presence,an amount of Primary fluid would flow backward into the Secondarycontainer through the opened sealable component 722, while still anotheramount of Primary fluid would continue to flow to the infusion pump 728.However, this backflow into the Secondary container wouldn't be safe incases such as chemo delivery. It would be unsafe for there to be anyfluid in the Secondary container that once contained the chemo.

Thus, the advantages of integrating the example first drip chamber 206A(including the check valve 210) along the Secondary pathway togetherwith the tubing clamp 706 and the vacuum activated catch 710 include atleast saving costs, creating a safer environment and the simplicity ofits design that renders significant benefits.

All statements herein reciting principles, aspects, and embodiments aswell as specific examples thereof, are intended to encompass bothstructural and functional equivalents thereof. Additionally, it isintended that such equivalents include both currently known equivalentsand equivalents developed in the future, i.e., any elements developedthat perform the same function, regardless of structure. The scope ofembodiments, therefore, is not intended to be limited to the embodimentsshown and described herein. Rather, the scope and spirit of embodimentsare embodied by the appended claims.

What is claimed is:
 1. A flow control system comprising: a tubing clampcomprising: a clamping mechanism configured for holding closed a firstfluid line while a second fluid flows along a second fluid line from asecond container, said first fluid line configured for delivering a flowof a first fluid; a drip chamber coupled with and between said secondcontainer and said second fluid line, said drip chamber comprising: afirst end comprising an inlet; a second end comprising an outlet; aspike integrally coupled with said first end; a drip forming orificecoupled with said spike; a check valve disposed between and coupled withsaid spike and said drip forming orifice, said check valve configuredfor managing fluid flowing between said inlet and said outlet through aninterior flow passage extending at least through said spike, said dripforming orifice and said check valve; an enclosing wall coupling saidfirst end with said second end, said enclosing wall housing within atleast said spike, said check valve and said drip forming orifice; and asealable component configured for sealing closed said interior flowpassage within said drip chamber when said second container issubstantially empty, thereby obstructing said flow of said second fluid;a vacuum activated catch retainably coupled with said tubing clamp andcoupled with said second fluid line, said vacuum activated catchcomprising: a movable element coupled with said tubing clamp andconfigured for changing from a first shape to a second shape uponreceipt of a deforming pressure, wherein when said movable element is insaid first shape, said vacuum activated catch retains said tubing clampin a closed position, and when said movable element is in said secondshape, said vacuum activated catch releases said tubing clamp into anopen position, thereby allowing said flow of said first fluid tocommence within said first fluid line; and an infusion pump coupled withsaid first and second fluid lines, said infusion pump configured fordrawing a vacuum in said second fluid line, thereby creating saiddeforming pressure when said second container is said substantiallyempty.
 2. The drip chamber of claim 1, further comprising: a pressuredamping elastic component comprising: an air holding portion of saiddrip chamber, said air holding portion configured for holding air; andat least a portion of said enclosing wall having an elasticity, whereinsaid air holding portion and said at least a portion of said enclosingwall having an elasticity are configured for damping a pressure pulsefrom an infusion pump, said infusion pump being fluidly coupled withsaid drip chamber.
 3. The drip chamber of claim 1, further comprising: apressure damper configured for shielding said check valve from anegative transient pressure, said pressure damper comprising: a flowresistance channel configured for providing a hydraulic resistance to afirst fluid flowing in a first direction from said outlet to said inlet;and a pressure damping elastic component comprising: an air holdingportion of said drip chamber, said air holding portion configured forholding air; and at least a portion of said enclosing wall having anelasticity, wherein said air holding portion and said at least a portionof said enclosing wall having an elasticity are configured for damping apressure pulse from an infusion pump, said infusion pump being fluidlycoupled with said drip chamber.
 4. The drip chamber of claim 1, whereinsaid check valve is a one-way check valve configured for allowing asecond fluid to flow in a second direction within said interior flowpassage and stopping a first fluid from flowing in a first directionwithin said interior flow passage, wherein said first direction isopposite said second direction.
 5. The drip chamber of claim 1, whereinsaid drip forming orifice comprises: a flow resistance channelconfigured for providing a hydraulic resistance to a first fluid flowingfrom said outlet to said inlet.
 6. The drip chamber of claim 1, whereinsaid check valve comprises: a bypass mechanism configured for openingsaid check valve in response to receiving an opening trigger, therebyreleasing a first fluid flowing in a first direction through said checkvalve from said outlet to said inlet.
 7. The drip chamber of claim 6,wherein said opening trigger is a threshold pressure of said first fluidflowing from said outlet to said inlet.
 8. The drip chamber of claim 6,wherein said opening trigger is a threshold force applied against saidcheck valve, thereby deforming said check valve from a first shape to asecond shape.
 9. The flow control system of claim 1, wherein saidmovable element is secured by and releasable from said tubing clamp as aresult of a displacement of said movable element reacting to a vacuumproduced by said infusion.
 10. The flow control system of claim 1,wherein said tubing clamp further comprises: a first arm; and a secondarm coupled with said first arm via a connector, wherein said connectoris flexible.
 11. The flow control system of claim 10, wherein saidmovable element comprises: a first attachment portion; and a secondattachment portion, wherein said first attachment portion and saidsecond attachment portion of said movable element are coupled with ahooked end of said second arm of said tubing clamp.
 12. The flow controlsystem of claim 10, wherein said movable element of said vacuumactivated catch is configured for securing said first arm of said tubingclamp while said movable element is in said first shape such that saidfirst fluid line is pinched closed.
 13. The flow control system of claim10, wherein said movable element of said vacuum activated catch isconfigured for releasing said first arm of said tubing clamp while saidmovable element is in said second shape such that said first fluid lineis opened.
 14. The flow control system of claim 1, wherein said sealablecomponent is a ball float valve, said ball float valve comprising: aball; and a base, wherein when said second container is empty, said ballsits within said base, thereby sealing said second fluid line.
 15. Theflow control system of claim 1, wherein said sealable component is afilter.
 16. The flow control system of claim 15, wherein said filtercomprises: a pore diameter configured for producing a bubble pointpressure that activates said movable element, thereby releasing saidvacuum activated catch that is closing said first fluid line.
 17. Theflow control system of claim 1, wherein said deforming pressure is anegative pressure.